Some results of evaluation of new-introduced apricot cultivars under conditions of Plovdiv region

V. Bozhkova*, M. Nesheva

Fruit Growing Institute, 4004 Plovdiv, Bulgaria
(Manuscript received 15 May 2016; accepted for publication 24 August 2016)

Abstract.ApricotisnottypicalspeciesforSouthCentralRegionofBulgaria,wherethePlovdivregionoccupiesalargepart oftheterritory,butlast5yearsthe area and production remain stable. In this study, are presented the first results of investigation on seven new introduced apricot cultivars ‘Bergecot’, ‘Flavor cot’, ‘Jenny cot’, ‘Lady cot’, ‘Perle cot’, ‘Sweet cot’ and ‘Tom cot’, carried out at the Fruit Growing Institute in Plovdiv. The investigation included phelogical data, fruit dimensions, chemical composition and sensory evaluation of the fruits. The studied cultivars more often entered the stage of flowering after second part of March and the differences between them were insignificant – one or two days. Among the investigated cultivars four of them ripened in the third decade of June, ‘Lady cot’ ripened in the beginning of July, ‘Bergecot’ in the end of July and ‘Jenny cot’ in the first half of August. The largest fruits had cultivar ‘Lady cot’ – 57.86 g, andthesmallestone’Flavorcot’–37.64g.Thetotalsolublesolids(TSS)contentinthepresentstudyvariedfrom13.4°Brixin’Perlecot’to23.3°Brix in’Jeny cot’ cultivar. The highest vitamin C content was found in ‘Bergecot’ – 29.40 mg/100 g and it is statistically proved. According to the final evaluation the cultivars ‘Bergecot’ and ‘Sweet cot’ have exellent sensory characteristics and the other 5 cultivars are classified in the group of first class. According to the obtained data, all evaluated cultivars in this study are suitable for growing under the conditions of Plovdiv region. The most attractive and quality fruits have cultivars ‘Lady cot’, ‘Perle cot’, ‘Bergecot’ and ‘Sweet cot’.


Amino acid composition of lamb meat from the North East Bulgarian fine fleece breed and its crossbreds with Australian merino and Ile de France from internal breeding

R. Slavov1*, G. Mihaylova1, St. Ribarski2, D. Panayotov1, D. Pamukova1, D. Dragnev1

1Department of Animal Science – Ruminants and Dairy Farming, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Department of Morphology, Physiology and Nutrition, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 1 May 2016; accepted for publication 25 August 2016)

Abstract. A comparative analysis of amino acid composition of lamb meat from the North East Bulgarian fine fleece breed (I gr.) and its crossbreds from internal breeding with 25% heredity from the Australian merino (II gr.) and Ile de France (III gr.) breeds was conducted. Upon starting the experiment lambs were equal and during the experiment they were placed under similar conditions of feeding and rearing. To establish the amino acid composition of meat slaughter analyses were performed at 100 and 130 days of age. From the carcass of each slaughtered animal individual mean samples were taken. Studies were carried out in the Research Laboratory of the Faculty of Agriculture at Trakia University. As a result of the studies the following conclusions were made: 1⁄4 Ile de France crossbreds in a sophisticated crossing have the highest total amino acid content, including essential amino acids in the meat of 100- and 130-day-old lambs, 6.87% and 7.36%, respectively. The lysine/arginine ratio, relating to protein atherogenicity, varies within narrow ranges among groups and marks slight increase with age – from 1.31-1.37 at 100 days to 1.41-1.46 at 130 days. With the increase of age in crossbreds from internal breeding total protein amino acid content grows, that being most prominent in lambs from the III group – from 41.92 to 43.49%. The values of total protein indices increase compared to the reference protein (from 117.97% to 118.22% for II group and from 116.44% to 120.80% for III group) and the whole egg protein (from 89.39% to 91.92% for II group and from 90.53% to 93.93 for III group). It has been found that internal breeding of crossbreds with 25% heredity from the Ile de France breed has positive effect concerning the total amino acid content of lamb meat at 100 and 130 days of age, essential amino acid content in it and the levels of total amino acid indices. Internal breeding of crossbreds with 25% heredity from the Australian merino breed does not have an adverse effect on the levels of the studied traits.


Quality traits of eggs from autosexing Easter eggers

H. Lukanov1*, A. Genchev1, A. Pavlov2, I. Penchev1

1Department Animal Science – monogastric and other animals, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Pharmacology, Physiology of animals and Physiological chemistry, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 5 July 2016; accepted for publication 31 August 2016)

Abstract. The main egg quality traits were investigated in two autosexing F1 Easter egger crosses. Partridge Araucana roosters were used as carriers of the eggshell biliverdin pigmentation gene. Maternal forms used for obtaining the two experimental crosses were high-producing layer hens carrying the sex-linked S and B genes. Experimental groups comprised F1 crosses of partridge Araucana roosters with white mutational Rhode Island hens or hens with barred colour mutation. The aim of the study was to investigated the quality traits of blue-green eggs produced by autosexing hens. The egg quality was evaluated at 38 weeks of age. Studied traits comprised egg weight (g), shape index, albumen index (AI), Haugh units (HU), yolk index (YI), yolk colour (Roche scale), percentages of albumen, yolk and eggshell (%), eggshell surface (cm2), eggshell density (mg/cm2), average eggshell thickness (μm) and eggshell colour. The group W was outlined with the highest egg weight – 61.03±0.47 g, and group A – with the lowest (50.91±0.32 g). The albumen and yolk quality was the best in group A, where albumen index was 0.075±0.002, Haugh units – 76.53±0.8 and yolk index – 0.491±0.009. The analysis of eggshell colour showed that eggs of group A were with the highest lightness (L*) value (73.60±0.77), whereas eggs of groups W and AW had egg lightness of 60.45±0.53 and 61.11±0.55 (p<0.001) respectively. The shell colour index (SCI) demonstrated a certain overlap of values in eggs with protoporphyrin and biliverdin taints. After introduction of a correction coefficient and recalculation of SCI*, the values of green eggs assumed a negative sign and could be distinguished from brown eggs.


Phytosanitary conditions of the organic field and boundary

D. Atanasova1*, V. Maneva1, N. Grozeva2

1Institute of Agriculture, Karnobat, Bulgaria
2Department of Biology and Aquaculture, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 1 July 2016; accepted for publication 11 August 2016)

Abstract. In the field and boundary of certificated field for organic farming in the Institute of Agriculture – Karnobat have been observed and described diseases, pests and weeds in wild and cultivated plants and dependencies between them are reported. The cultural plant diversity at the certified field for organic farming is significant and amounts to 32 species and varieties of cereals. The weeds in crops and in the free areas significantly differed. In crops, the annual broadleaf weeds had greater diversity of species (Anthemis arvensis L., Lathyrus aphaca L., Papaver phoeas L., Polygonum aviculare L., Polygonum convolvulus L.) and at the boundaries – the cereal weeds (Аpera spica-venti L., Hordeum murinum L., Bromus tectorum L., Poa pratensis L.). At the adjacent areas the perennial broadleaf weeds – Cirsium arvense (L.) Scop. and Convolvulus arvensis L. were not found. At the boundaries less pest species and types of diseases were registered than in the crop fields. In cereals the most common pests are Sitobion avenae L., Aelia acuminate L., Eurygaster austriaca Schr. Beneficial insects are Coccinella septempunctata L. The most common diseases are Erysiphe graminis and Rhynchosporium secalis (Oudem.) Davis.


Effect of some soil herbicides on vegetative habits of almond trees of ‘Nonpareil’ cultivar grown in a second-year nursery field

Z. Rankova1*, M. Tityanov2

1Fruit Growing Institute, 4004 Plovdiv, 12 Ostromila, Bulgaria 2University of Forestry, 10 Kliment Ohridski, 1756 Sofia, Bulgaria

(Manuscript received 31 May 2016; accepted for publication 26 July 2016)

Abstract. The study was carried out in the period 2010 – 2012 in a nursery field established on the territory of the Fruit-Growing Institute, Plovdiv. The effect of the combined soil-applied herbicide metolachlor + oxyfluorfen (Metofen) and the contact soil herbicide with foliar activity flumioxazine (Pledge 50 WP) on the vegetative habits of ‘Nonpareil’ almond cultivar grafted on almond seedling rootstock was evaluated. In the period 15-25 March, before beginning of vegetation, soil herbicides were applied in the row strip in the second-year nursery field. The following variants were included in the study: 1. Control (untreated, hand- weeded); 2. Metofen – 120 ml/da; 3. Metofen – 240 ml/da; 4. Pledge 50 WP – 8.0 g/da; 5. Pledge 50 WP – 20.0 g/da. The effect of the herbicides on weed infestation and on the vegetative habits of the cultivar/rootstock combination ‘Nonpareil’/almond seedling rootstock was followed up. The results showed that the herbicides applied at the tested rates had a good control on weed infestation and the herbicide activity continued for 3.5-4 months. That makes it possible to eliminate the competitive impact of weeds on the development of the grafted trees for 4-5 months after beginning of vegetation. Visual symptoms of phytotoxicity (chlorosis or necrosis in the leaves and shoots) or an obvious suppression of the development of the grafted trees in the treated variants were not established. A depressing effect on growth of the grafted trees was reported after treatment with Metofen. The contact herbicide with soil and foliar activity Pledge 50 WP – 8.0 g/da can be applied for weed control in a second-year nursery field of almond trees grafted on bitter almond seedling rootstock.


Selectivity and stability of herbicides and herbicide combinations for the grain yield of maize (Zea Mays L.)

G. Delchev1*, T. Barakova2

1Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Field Crops Institute, 6200 Chirpan, Bulgaria

(Manuscript received 16 May 2016; accepted for publication 9 August 2016)

Abstract. The research was conducted during 2012 – 2014 on pellic vertisol soil type. Under investigation was cycloxydim tolerant maize hybrid Ultrafox duo (Zea mays L.). Factor A included the years of investigation. Factor B included no treated check and 3 soil-applied herbicides – Adengo 465 SC (isoxaflutol + tiencarbazon) – 440 ml/ha, Wing P (pendimethalin + dimethenamid) – 4 l/ha and Lumax 538 SC (S-metolachlor + terbuthylazine + mesotrione) – 4 l/ha. Factor C included no treated check and 5 foliar-applied herbicides – Stellar 210 SL (topramezon + dicamba) – 1 l/ha, Principal plus (nicosulfuron + rimsulfuron + dicamba) – 380 g/ha, Ventum WG (foramsulfuron + iodosulfuron) – 150 g/ha, Monsun active OD (foramsulfuron + tiencarbazon) – 1.5 l/ha and Laudis OD (tembotrione) – 2 l/ha. In addition to these variants by conventional technology for maize growing one variant by Duo system technology is also included in the experiment. It includes soil-applied herbicide Merlin flex 480 SC (isoxaflutole) – 420 g/ha and tank mixture of antigraminaceous herbicide Focus ultra (cycloxydim) – 2 l/ha + antibroadleaved herbicide Kalam (tritosulfuron + dicamba) – 300 g/ha. It is found that herbicide combination of soil-applied herbicide Merlin flex with tank mixture Focus ultra + Kalam by Duo system technology leads to obtaining high grain yield. High yields of maize grain are also obtained by herbicide combinations Lumax + Principal plus, Lumax + Laudis and Wing + Principal plus. The most unstable are the non-treated check and single use of soil- applied herbicides Adengo, Wing and Lumax. Technologically the most valuable are herbicide combination Merlin flex + Focus ultra + Kalam by Duo system technology, followed by combinations of foliar-applied herbicides Principal plus and Laudis with soil-applied herbicides Adengo, Wing and Lumax by conventional technology. Single use of herbicides has low estimate due to must to combine soil-applied with foliar-applied herbicides for full control of weeds in maize crops


Influence of foliar herbicides treatment on malting barley (Hordeum vulgare L.) productivity of Emon, Vanessa and Vicky varieties

D. Atanasova*, V. Maneva

Institute of Agriculture, 8400 Karnobat, Bulgaria
(Manuscript received 1 July 2016; accepted for publication 26 August 2016)

Abstract. During the period 2012 – 2014 in the Institute of Agriculture, Karnobat a field experiment was conducted with winter malting barley varieties Emon, Vanessa and Vicky. The influence of broadleaf (dicotyledonous) herbicides alone and in their combination with wild oat (monocotyledonous) in tillering stage of the crop was studied in optimal and double doses. The herbicide selectiveness was assessed according to the EWRS scale. Yields were reported after harvest. In variety Vanessa during the treatment with Derby Super, Granstar Super, Sekator OD and combination of Puma Super 7.5 EW + Sekator OD in optimal doses, the yield does not differ from the weed control. Variety Vicky endures well the treatment with optimal doses in all of the tested herbicides, except Husar Max. In treatment with double doses, only Granstar Super does not affect negatively the yield of grain. Comparing the data from ANOVA about the role of herbicides and year conditions on the malting barley varieties it can be concluded that the yield of variety Emon is the most stable in regard to herbicides applied in optimal doses (5%), followed by Vanessa (17%) and Vicky (18%). At application of the herbicides in double doses, their influence is increased – in variety Emon up to 15%, and in varieties Vanessa and Vicky – up to 23%.


Effect of some herbicides on weeds and vines in mother plantation of Cabernet sauvignon

N. Prodanova – Marinova*

Institute of Viticulture and Enology, 5800 Pleven, Bulgaria
(Manuscript received 1630 May 2016; accepted for publication 17 August 2016)

Abstract. To maintain soil surface clean of weeds in the parent vineyard for producing cuttings for scions, the efficiency and selectivity of Gardoprim plus Gold (312.5 g/l s-metolachlor + 187.5 g/l terbuthylazine), Wing P (pendimethalin 250 g/l + dimethenamid P 212.5 g/l) and Lumax 538 SC (375 g/l s-metolachlor + 125 g/l terbuthylazine + 337.5 g/l mesotrione) at doses of 0.4 and 0.6 l/da was studied. Lumax 538 SC, Wing P and Gardoprim Plus Gold controlling efficiently annual weeds established in parent vineyard, except Xanthium strumarium L.. Lumax 538 SC and Gardoprim plus Gold showed long-term (90 days) activity. Wing P activity decreases after the thirtieth day. The tested herbicides do not damage the buds and do not lead to a reduction of shoots developed from them. Lumax 538 SC and Gardoprim plus Gold at doses of 0.4 and 0.6 l/da and Wing P at dose of 0.4 l/da do not inhibit the growth of shoots. The largest number of cuttings for scions were obtained after treatment with Lumax 538 SC.


Grain combines productivity according to various unloading methods – in the field and at the edge of the field

N. Delchev1*, K. Trendafilov2, G. Tihanov1, Y. Stoyanov1

1Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Machine Engineering, Faculty of Engineering and Technologies – Yambol, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 3 July 2016; accepted for publication 23 August 2016)

Abstract. Grain tank unloading is usually done at a standstill. In some cases the combine has to leave the processed strip and to unload in a vehicle located outside the field. The publication analyses the reasons for unloading grain tanks by leaving the processed strip and the impact of this type of unloading on the combine productivity compared to unloading the grain tank in the field itself. A study has been performed in Bulgarian farms using different ways of unloading and the results of time measured for unloading grain tanks in and at the end of the field have been given when harvesting various agricultural crops. The combine productivity when unloading in the field and at the edge of the field has been compared. It has been determined that when unloading at the edge of the field the productivity is approximately 11% lower than the productivity during unloading at a standstill in the field.


Influence of the year characteristics and the different fertilization levels on the structural elements of wheat yield

V. Kuneva1*, R. Bazitov2, A. Stoyanova3

1Department of Mathematics, Informatics and Physics, Faculty of Economics, Аgricultural University, Plovdiv, Bulgaria 2Agricultural Institute, 6000 Stara Zagora, Bulgaria
3Department of of Plant Production, Faculty of Agriculture, Thracian University, 6000 Stara Zagora, Bulgaria

(Manuscript received 1 May 2016; accepted for publication 24 June 2016)

Abstract. The aim of the development is (through two-way dispersion analysis – ANOVA) to study the impact of the factors “year characteristics” and “fertilization levels” on the separate biometric indicators for wheat: ear length (cm), ear-bearing stems (cm), number of grains per ear (num.), grain weight per ear (g) and mass of 1000 grains (g). Data for the yield and its structural elements were used. They were obtained through a field experiment conducted in the period 2009 – 2011, on a meadow-cinnamon soil in the experimental field at Agricultural Institute – Stara Zagora. With high degree of reliability the impact of the examined factors and their interaction on the following indicators was statistically proven: length of wheat-ear (cm), ear-bearing stems (cm), number of grains per ear (N), grain weight per ear (g), mass of 1000 grains (g). The strongest impact on the given factors has the factor “fertilization levels” for the indicator “ear- bearing stems” (96%).